Datalog midend stage

[verytactical]

In order to simplify development of tree operations and computing complex fixpoint operations, we need an intermediate datalog stage.

• Compile souffle-js
• Write temporary AST -> datalog converter
• Write some simple, but interesting operations on it (resolving, optimization etc)
• Check performance on real-world contracts
• Make a codegen that
  • takes AST types + souffle code without .type statements
  • generates .type statements from TS types, and concatenates them
  • generates bindings for code that
    • serializes .input CSV from values of those TS types
    • calls souffle on source from previous step
    • deserializes .output CSV to values of those types